Among various automobile components, a few of them are made from a pair of sheet metal parts connected together and positioned to oppose with each other, e.g., brake pedals used for brake pedal systems of automobiles. Brake pedals of these days are often used as hollow components in order to make them lighter in weight, comprising a pair of sheet metal parts that are positioned to oppose with each other and connected at their fringe areas.
A conventional brake pedal system of automobiles comprises: a bracket attached to the dashboard panel; a brake pedal whose top portion is mounted on a support shaft which is rotatably mounted on the bracket; and a rod one end of which is connected to a pin that goes through the top area of the brake pedal, while the other end is connected to master vac (not shown) (see, for example, Patent Document 1 below).
In such a brake pedal system, stepping on the brake pedal causes the stepping force to be transmitted to the master vac via the connecting part between said brake pedal and the rod, resulting in a large force being applied to the connecting part. Therefore, the connecting part has hitherto been so constructed as to have a sufficient strength by piercing a prepared hole in the brake pedal, welding a pipe to said prepared hole, inserting a pin into the pipe, and connecting the end of the rod to the pin. The manufacture of such a brake pedal requires the prepared hole machining of the brake pedal and welding of the pipe, so that it is not only undesirable from the cost standpoint due to the cost of the pipe and welding cost, but also from the standpoint of man-hour and work environment.
Therefore, due to the demands for weight reduction of vehicle components in general, brake pedals have come to be manufactured lately by assembling a pair of preformed thin sheet metal parts together to form a hollow body and bending the peripheral edge to connect them together. Such a brake pedal is lighter in weight because it is generally hollow in shape, does not require any welding as it is assembled by press-forming the peripheral edge, and causes a desirable work environment.